diff --git a/mesh-doctor/src/geos/mesh_doctor/actions/euler.py b/mesh-doctor/src/geos/mesh_doctor/actions/euler.py
index b72504ab..92d5a129 100644
--- a/mesh-doctor/src/geos/mesh_doctor/actions/euler.py
+++ b/mesh-doctor/src/geos/mesh_doctor/actions/euler.py
@@ -52,6 +52,7 @@ class SurfaceComponent:
     numBoundaryEdges: int
     numNonManifoldEdges: int
     interpretation: str
+    nonManifoldEdgeEndpoints: tuple[ tuple[ int, int ], ...] = field( default_factory=tuple )
 
 
 @dataclass( frozen=True )
@@ -152,6 +153,7 @@ def __countConnectedComponents( mesh: vtk.vtkUnstructuredGrid ) -> int:
     cf = vtk.vtkConnectivityFilter()
     cf.SetInputData( mesh )
     cf.SetExtractionModeToAllRegions()
+    cf.SetRegionIdAssignmentMode( vtk.vtkConnectivityFilter.CELL_COUNT_DESCENDING )
     cf.ColorRegionsOn()
     cf.Update()
     return cf.GetNumberOfExtractedRegions()
@@ -229,6 +231,7 @@ def __surfaceComponentsFromColored( colored: vtk.vtkUnstructuredGrid ) -> list[
     """Compute (V, E, F, chi, boundary, non-manifold) per RegionId of a colored 2D mesh."""
     rid = vtk_to_numpy( colored.GetCellData().GetArray( "RegionId" ) ).astype( np.int64 )
     cells = colored.GetCells()
+    # GetConnectivityArray / GetOffsetsArray require VTK 9+
     conn = vtk_to_numpy( cells.GetConnectivityArray() ).astype( np.int64, copy=False )
     off = vtk_to_numpy( cells.GetOffsetsArray() ).astype( np.int64, copy=False )
 
@@ -251,7 +254,8 @@ def __surfaceComponentsFromColored( colored: vtk.vtkUnstructuredGrid ) -> list[
         E = len( edgeCount )
         F = int( len( sel ) )
         bE = sum( 1 for c in edgeCount.values() if c == 1 )
-        nm = sum( 1 for c in edgeCount.values() if c > 2 )
+        nmEdges = tuple( ek for ek, c in edgeCount.items() if c > 2 )
+        nm = len( nmEdges )
         chi = V - E + F
         components.append(
             SurfaceComponent( componentId=int( regionId ),
@@ -262,7 +266,8 @@ def __surfaceComponentsFromColored( colored: vtk.vtkUnstructuredGrid ) -> list[
                               eulerCharacteristic=chi,
                               numBoundaryEdges=bE,
                               numNonManifoldEdges=nm,
-                              interpretation=__interpretSurface( chi, bE, nm ) ) )
+                              interpretation=__interpretSurface( chi, bE, nm ),
+                              nonManifoldEdgeEndpoints=nmEdges ) )
     return components
 
 
diff --git a/mesh-doctor/src/geos/mesh_doctor/parsing/eulerParsing.py b/mesh-doctor/src/geos/mesh_doctor/parsing/eulerParsing.py
index 1ad7dcfa..7af5061e 100644
--- a/mesh-doctor/src/geos/mesh_doctor/parsing/eulerParsing.py
+++ b/mesh-doctor/src/geos/mesh_doctor/parsing/eulerParsing.py
@@ -131,6 +131,13 @@ def __displaySurfaceGroup( g: SurfaceGroup ) -> None:
         setupLogger.results( "  " + f"{c.componentId:>5} {c.numCells:>9,} {c.numVertices:>8,} {c.numEdges:>8,} "
                              f"{c.numFaces:>8,} {c.eulerCharacteristic:>5} {c.numBoundaryEdges:>6,} "
                              f"{c.numNonManifoldEdges:>4,}  {c.interpretation}" )
+        if c.nonManifoldEdgeEndpoints:
+            _MAX_DISPLAY = 10
+            shown = c.nonManifoldEdgeEndpoints[ :_MAX_DISPLAY ]
+            setupLogger.results( "    non-manifold edge endpoints (point id pairs): "
+                                 + ", ".join( f"({a},{b})" for a, b in shown )
+                                 + ( f" … (+{len(c.nonManifoldEdgeEndpoints)-_MAX_DISPLAY} more)"
+                                     if len( c.nonManifoldEdgeEndpoints ) > _MAX_DISPLAY else "" ) )
     if len( g.components ) > 1:
         setupLogger.results( f"  WARNING: {len(g.components)} components — verify isolated cells" )